From 2bb3e259d0410f16a8b2058a05af434376a1583a Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Fri, 26 Jul 2019 09:57:32 -0700
Subject: [lttng-ust][PATCH] Add config time check for new gettid API

glibc 2.30 introdoced this function see [1]
so its best to detect it
and provide fallbacks only if its not present

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=6399

Upstream-Status: Submitted [https://lists.lttng.org/pipermail/lttng-dev/2019-July/029131.html]

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 configure.ac            | 1 +
 include/lttng/ust-tid.h | 7 +++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7fa059a..b1099c1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -137,6 +137,7 @@ AC_CHECK_FUNCS([ \
 	clock_gettime \
 	ftruncate \
 	getpagesize \
+	gettid \
 	gettimeofday \
 	localeconv \
 	memchr \
diff --git a/include/lttng/ust-tid.h b/include/lttng/ust-tid.h
index e669d7e..7995c78 100644
--- a/include/lttng/ust-tid.h
+++ b/include/lttng/ust-tid.h
@@ -26,7 +26,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-
+#include <config.h>
+#if HAVE_GETTID
+#include <unistd.h>
+#else
 #ifdef __linux__
 #include <syscall.h>
 #endif
@@ -49,5 +52,5 @@ static inline pid_t gettid(void)
 	return getpid();
 }
 #endif
-
+#endif /* HAVE_GETTID */
 #endif /* _LTTNG_UST_TID_H */
-- 
2.22.0